Anionic bituminous emulsions

ABSTRACT

This invention relates to rapid set, medium set, and slow set anionic emulsions prepared from straight bitumen or bitumen modified by the incorporation of polymers, solvents, or polymer latices. Particularly, the invention relates to improved methods for enhancing adhesion between the asphalt and the aggregate in avionic solventless and solvent-containing bituminous emulsions wherein the emulsifiers are alkali earth salts of tall oil fatty acids, fortified tall oil fatty acids, tall oil rosin and fortified rosin as well as combinations of kraft lignin and nonionic emulsifiers. The adhesion promoters utilized in these improved methods are the reaction products of styrene (α-methyl styrene)-acrylic (metacrylic) acid polymers with polyalkylene amines. Further improvement can be obtained by using tall oil fatty acid or fortified tall oil fatty acids as co-reactants in the production of the polyamidoamine products.

FIELD OF INVENTION

This invention relates to rapid set, medium set, and slow set anionic emulsions prepared from straight bitumen or bitumen modified by the incorporation of polymers such as styrene butadiene rubbers (SBR), styrene block copolymers (SBS), ethylene vinyl acetate copolymers (EVA), and other suitable modifiers. The invention also relates to emulsions modified by the incorporation of solvents (such as diesel oil or kerosene) or by the addition of polymer latices (such as SBR-latex or natural rubber latex). More particularly, the invention relates to improved methods for enhancing adhesion between asphalt and aggregate in anionic solventless and solvent-containing bituminous emulsions wherein the emulsifiers are alkali earth salts of tall oil fatty acids, fortified tall oil fatty acids, tall oil rosin and fortified rosin as well as combinations of kraft lignin and nonionic emulsifiers. The adhesion promoters utilized in these improved methods are the reaction products of styrene (α-methyl styrene)-acrylic (metacrylic) acid polymers with polyalkylene amines. Further improvement can be obtained by using tall oil fatty acid or fortified tall oil fatty acids as co-reactants in the production of the polyamidoamine products.

BACKGROUND OF THE INVENTION

In paving operations, three main practices are employed to achieve thorough mixing of bitumen and aggregate:

(1) mixing of free flowing heated asphalt (asphalt cement) with pre-dried aggregate,

(2) mixing pre-dried aggregate with asphalt diluted with a hydrocarbon solvent (cutback asphalt, cutter stock) at ambient or slightly elevated temperatures, and

(3) mixing aggregate with asphalt emulsions, e.g., oil in water emulsions, obtained by vigorous agitation of asphalt and water in the presence of an emulsifying agent.

The escalating costs of energy and hydrocarbon solvents coupled with a heightened environmental awareness have stimulated increases in the use of emulsified asphalts in the road paving industry. The type of emulsifier employed is determined by the desired application of the asphalt emulsion. For rapid set emulsions (mainly used for chip sealing) sodium soaps of tail oil are commonly utilized. For medium set emulsions (applied in cold mixes of virgin aggregate or reclaimed asphalt pavement) higher concentrations of tall oil or modified tall oil soaps are generally being used with and without the addition of moderate amounts of hydrocarbon solvent. Slow set emulsions with good mix stability in the presence of fine graded aggregate are usually based on vinsol (a by-product of the wood rosin manufacture), on fortified tall oil rosin in combination with kraft lignin or lignosulfonates, and combinations of kraft lignin or lignosulfonates with nonionic emulsifiers from the class of ethoxylated alkylphenols, ethoxylated linear or branched fatty alcohols and of ethylene oxide-propylene oxide-block co-polymers. In anionic emulsions the asphalt droplets are stabilized by anionic surfactants (wherein their negatively-charged surface migrates to the anode when an electric field is applied).

In the case of rapid set emulsions (mainly used for repair work of old wearing courses) the emulsion is applied on the existing surface and aggregate is spread on top. After the water of the emulsion has evaporated, an intimate matrix of asphalt and stone with good load beating capacity is formed. The road can be re-opened to traffic shortly after application of the seal. Medium set emulsions are commonly being mixed with aggregate in a pug mill prior to being used in road construction. The incorporation of solvent allows the mixes to be stock piled prior to use. The mixes are prepared in central mixing plants and transported to the job sites or are generated "in-place". Slow set emulsions are being applied where good penetration and wetting is necessary. Mixes with high loadings of fines, base stabilization and tack coat are the main applications.

Anionic emulsions are taught by Mertens in U.S. Pat. No. 3,062,829 to be prepared via the use of alkali hydroxide which saponify the surface active acids naturally occurring in asphalt. These emulsions contain high molecular weight polyamides (Versene) as viscosity reducers and adhesion promoters. In U.S. Pat. No. 3,108,971 to Mertens anionic emulsions of the same type are improved with the addition of alkanol amines lacking lipophilic characteristics. Lignin amines are taught by Borgfeldt in U.S. Pat. No. 3,123,569. Quick setting emulsions obtained from highly acidic asphalts using lithium hydroxide are disclosed by Mertens in U.S. Pat. No. 3,240,716. Montgomery and Pitchford teach the alkali metal salts of complex polynuclear aromatic polycarboxylic acids as anionic emulsifiers in U.S. Pat. No. 3,344,082. Heinz in U.S. Pat. No. 3,006,860 employs alkali metal soaps of higher fatty acids such as those found in tall oil. In U.S. Pat. Nos. 3,956,002 and 4,088,505 Moorer teaches anionic emulsifiers consisting of alkali lignin or oxygenated alkali lignin, an ethylene oxide adduct of alkylphenol and up to 10% by weight of sodium borate. Detroit describes in U.S. Pat. No. 4,293,459 combinations of partially desulfonated oxygenated lignosulfonates and nonionic surfactants. Schilling et al. disclose the alkali soaps of maleated or fumarated tall oil fatty acids or rosin, of DIACID® 1550 and of sulfonated tall oil fatty acid as emulsifiers for anionic high float emulsions in U.S. Pat. No. 4,676,927 and the use of carboxyethylated modified tall oil amidoamines as emulsifiers for anionic slurry seals in U.S. Pat. No. 4,561,901. Ferm in U.S. Pat. No. 3,740,344 teaches the preparation of quick set anionic slurry seal compositions by applying a combination of aryl alkyl sulfonates and ethylene oxide adducts of alkyl phenols and of fatty alcohols. Schreuders in U.S. Pat. No. 3,615,796 teaches the use of petroleum sulfonates. A combination of sodium lignate or lignosulfonate and saponified tall oil or rosin is disclosed in U.S. Pat. No. 3,594,201 by Sommer and Evans. In U.S. Pat. No. 3,350,321 Conn describes the use of alkyl or alkoxy alkyl phosphoric acid salts as emulsifiers for asphalt.

Anionic emulsions are generally prepared at emulsifier concentrations of 0.2-10.0% based on 100% activity, preferentially at 0.2 to 2.0%. The pH range is 7 to 14, preferentially at 10 to 12 in the case of tall oil and rosin soaps. The advantage of anionic emulsions lies in the relatively low cost of tall oil based emulsifiers. The disadvantage is the low bond strength of asphalt to aggregate once the emulsion has dried and formed a film of asphalt on the surface of the aggregate. As most of the aggregates are negatively charged, the electrostatic repulsion between the negatively charged asphalt and the negatively charged stones causes inferior adhesion. Highly acidic aggregates such as quartzite, granite, rhyolite and many of the sedimentary, metamorphic and igneous rocks are considered responsible for the existing bitumen-stripping problem. This problem is also encountered in hot mix applications and when cut back asphalts are being used.

The quality of the road surface is generally dependent upon the strength of the bonds between the asphalt and the aggregate after curing of the composition. Poor service performance is due to poor adhesion, which results in asphalt stripping off the aggregate surface. Asphalt compositions also have relatively poor adhesion to aggregate in the presence of water. Since the aggregate is preferentially wetted by water, the eventual penetration of water into the composition reaches the aggregate and interferes with the bond between aggregate and asphalt. The result of this stripping is flaked pavement and the formation of pot holes.

To reduce water-induced debonding of asphalt from the stone surface, in many cases surface-active amines or diamines are added to the asphalt. Generally, anti-stripping agents or adhesion promoters are introduced into the asphalt prior to the asphalt being mixed with the aggregate. In the case of anionic asphalt emulsions it is advantageous to add the additive to the emulsion to prevent degradation at the high pH values. The patent literature sets forth a large number of compounds which can be used to improve adhesion of asphalt to aggregate. These include ethylene oxide condensates of long chain alkyl triamines (U.S. Pat. No. 3,615,797), alkoxylated amines and their salts (U.S. Pat. No. 3,347,690), and reaction products of ozonized unsaturated fatty acids with polyalkylene amines (U.S. Pat. Nos. 3,246,008 and 3,245,451). Other additives are based on fatty carboxylic chromites (U.S. Pat. No. 3,963,509), on combinations of epoxy resins and onium borates (U.S. Pat. No. 3,947,395), on tall oil alkanol amines and amido amines (U.S. Pat. Nos. 2,679,462 and 4,806,166), on fatty ether amines in combination with alkanol amines (U.S. Pat. No. 3,928,061), and on fatty acid amido amine soaps (U.S. Pat. Nos. 2,426,220, 2,891,872 and 3,230,104). Aminoalkyl polyalkoxysilanes are disclosed in U.S. Pat. No. 3,861,933; and condensation products of amines, polyamines, and amides with formaldehyde are taught in U.S. Pat. No. 4,639,273. Mannich reaction products of polyamines with formaldehyde and alkylphenols are described in U.S. Pat. No. 4,789,402, and ethoxylated hexamethylenediamines and their derivatives are taught in European Patent Application No. 0 077 632 (82305420.0). Fatty primary, secondary and tertiary amines and imidazolines, their reaction products with various acids (including fatty acids), metal soaps, and several other compounds including rosin reaction products are described in U.S. Pat. No. 3,868,263.

One relatively inexpensive class of adhesion promoters which have shown promise for use in hot mix and in cut back asphalts are tall oil-based polyethylene amine condensation products. However, a major problem exists with such adhesion promoters in that their adhesion efficiencies are not high enough to obtain satisfactory results when they are utilized in anionic emulsions. It is, therefore, the object of this invention to solve this problem by disclosing an improved method for enhancing adhesion between asphalt and aggregate in anionic bituminous emulsions.

SUMMARY OF THE INVENTION

The objective of this invention is met by adding a polyamidoamine adhesion promoter to the anionic bituminous emulsion. Suitable polyamidoamine adhesion promoters are produced by reacting a styrene-acrylic acid copolymer (alone or blended with a tall oil fatty acid or rosin) in a condensation reaction with a polyamine (or blends of polyamines). A preferred method utilizes adhesion promoters produced by substituting up to 90% of the styrene-acrylic acid copolymer with a member selected from the group consisting of C₈ -C₂₀ fatty acids, C₉ -C₂₂ modified fatty acids of rosin, C₂₃ -C₂₄ modified rosins, or combinations thereof.

The improved methods for enhancing adhesion between asphalt and aggregate are effective even when utilized with traditionally recalcitrant, highly acidic aggregates. The adhesion promoting effects produced via the addition of these products are primarily due to the products' ability to migrate to the asphalt/aggregate interphase, where they hydrophobize the aggregate surface and render it water repellent. In addition, these products also increase adhesion by neutralizing some of the negative charges introduced into the asphalt by the anionic character of the emulsifier.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The improved method for enhancing adhesion between asphalt and aggregate in anionic bituminous (asphalt) emulsions comprises the addition to the emulsion of a composition comprising the polyamidoamine condensation reaction products of:

(A) 20-80 wt. % of a copolymer, formed by reacting

(1) 1-99 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with

(2) 99-1 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and

(B) 80-20 wt. % of a polyamine.

The process of producing these adhesion promoters (which are also effective as corrosion inhibitors for steel exposed to highly acidic environments) was disclosed by Schilling in U.S. Pat. No. 5,516,826 (which is hereby incorporated by reference). First, in a polymerization reaction (α-methyl) styrene reacts with a member selected from the group consisting of acrylic acid, metacrylic acid, their respective alkyl esters, and combinations thereof to form a styrene-acrylic acid copolymer. This copolymer is subsequently reacted in a condensation reaction with a polyamine or blend of polyamines to form the polyamidoamine adhesion promoter. These promoters do not contain any unreacted carboxylic acid groups. This chemical reaction scheme is shown below. ##STR1##

A preferred method for enhancing adhesion between asphalt and aggregate in anionic bituminous (asphalt) emulsions comprises the addition to the emulsion of a composition comprising the polyamidoamine condensation reaction products of:

(A) 30-70 wt. % of a copolymer, formed by reacting

(1) 20-80 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with

(2) 80-20 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and

(B) 70-30 wt. % of a polyamine.

The ratio of (α-methyl) styrene to acrylic acid (or metacrylic acid) required to yield the desired styrene-acrylic acid copolymers ranges from about 1:1 to 3:1. These copolymers are produced by heating in the presence of a suitable radical initiator the desired mixture of (α-methyl)styrene and acrylic acid (or metacrylic acid) to a temperature in the range of about 180°-270° C. for a time sufficient for the polymerization reaction to occur (usually about 1 to 20 min). This polymerization reaction is described in U.S. Pat. No. 4,546,160 by Brandt et al. (which is hereby incorporated by reference). Styrene-acrylic acid copolymers suitable for the practice of this invention have number average molecular weights in the range of about 1,000 to about 10,000. The ratio of styrene-acrylic acid copolymer to polyamine required to produce the desired polyamidoamine adhesion promoter is 1:1 to 2:1. These promoters are obtained by heating the desired mixture of styrene-acrylic acid copolymer and polyamine to a temperature in the range of about 180°-260° C. for a time sufficient for the condensation reaction to occur (usually about 2 to 8 hours).

A more preferred method for enhancing the adhesion of asphalt to aggregate in anionic bituminous emulsions comprises the addition to the emulsion of a composition comprising the polyamidoamine condensation reaction products of:

(A) 20-80 wt. % of a mixture containing:

(1) 20-80 wt. % of a copolymer formed by reacting

(a) 1-99 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with

(b) 99-1 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and

(2) 80-20 wt. % of a member selected from the group consisting of rosin, C₂₃ -C₂₄ modified rosins, C₈ -C₂₀ fatty acids, C₉ -C₂₂ modified fatty acids, and combinations thereof; and

(B) 80-20 wt. % of a polyamine.

The most preferred method for enhancing the adhesion of asphalt to aggregate in anionic bituminous emulsions comprises the addition to the emulsion of a composition comprising the polyamidoamine condensation reaction products of:

(A) 30-70 wt. % of a mixture containing:

(1) 20-80 wt. % of a copolymer formed by reacting

(a) 20-80 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with

(b) 80-20 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and

(2) 80-20 wt. % of a member selected from the group consisting of rosin, C₂₃ -C₂₄ modified rosins, C₈ -C₂₀ fatty acids, C₉ -C₂₂ modified fatty acids, and combinations thereof; and

(B) 70-30 wt. % of a polyamine.

Adhesion promoters suitable for use in these preferred methods are produced by replacing up to 80% of the styrene-acrylic acid copolymer with a member selected from the group of rosin (i.e. resin acid), C₂₃ -C₂₄ modified rosins, C₈ -C₂₀ fatty acids, C₉ -C₂₂ modified fatty acids, and combinations thereof. Fatty acids which are suitable for the practice of this invention have number average molecular weights in the range of about 100 to about 350. Sources of such suitable fatty acids include various animal fats and vegetable oils, glycerides, tall oil fatty acids, and petroleum-derived fatty acids. The term "tall oil fatty acid" refers generally to the class of products containing 90% or more fatty acids which are obtained by fractionation of crude tall oil. The fatty acids are primarily a combination of oleic and linoleic acids, with small amounts of saturated and other unsaturated fatty acids. Common impurities include rosin and neutral materials.

Modified C₉ -C₂₂ fatty acids suitable for the practice of this invention have number average molecular weights in the range of about 200 to about 470 and are produced by reacting in a Dieis-Alder cycloaddition polyunsaturated fatty acids (such as linoleic acid) with fumaric acid, maleic anhydride, itaconic acid, metacrylic acid, acrylic acid, or citric acid (after dehydration and decarboxylation) to produce cyclic polycarboxylic acids. (The Dieis-Alder reaction is described in the commonly assigned U.S. Pat. No. 5,194,640 to Cosgrove et al. which is hereby incorporated by reference.)

Reaction products of unsaturated fatty acid such as oleic acid or nonconjugated linoleic acid with maleic anhydride via the "ene"-reaction are also suitable as C₂₂ -fatty acid anhydrides. These types of tall oil fatty acid-derived anhydrides are described in U.S. Pat. No. 3,451,958 by Riedeman et at. (which is hereby incorporated by reference). Rosin suitable for the practice of this invention have number average molecular weights in the range of about 300 to about 350 and include wood rosin, gum rosin, and tall oil rosin. Modified C₂₃ -C₂₄ rosins suitable for the practice of this invention have number average molecular weights in the range of about 370 to about 470 and are produced by reacting in a Dieis-Alder cycloaddition rosin with fumaric acid, maleic anhydride, itaconic acid, metacrylic acid, acrylic acid, or citric acid after dehydration and decarboxylation to produce polycyclic polycarboxylic acid and acid anhydrides. (This Dieis-Alder reaction is described in the commonly assigned, U.S. Pat. No. 5,208,319 to Schilling, which is incorporated herein by reference.)

Polyamines which are suitable for the use in these methods have a number average molecular weight in the range of about 60 to about 1,000 and include many amines capable of forming an amidoamine when reacted with the polymer. Such polyamines include, but are not limited to, the following: aminoethylethanolamine, aminoethylpiperazine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexaethyleneheptamine, bis-aminopropylamine, pentamethylenediamine, hydroxyethylpiperazine, bis-hexamethylenetriamine, homologs, and combinations thereof.

Radical initiators which are suitable for the use in the above noted polymerization reactions include heat sensitive organic peroxides and azo compounds, and the like.

For application purposes it is preferred to produce adhesion promoters which are liquid in form. Therefore it may be necessary to adjust the viscosities of certain formulations by the addition of a solvent (a process well within the ability of a skilled artisan). Solvents which are suitable for use in the present methods include, but are not limited to, the following: ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, alkanolamines, and combinations thereof. Preferred alkanolamines suitable for use as a solvent include monoethanolamine, diethanolamine, triethanolamine, combinations thereof, and the like.

The following examples are provided to further illustrate the present invention and are not to be construed as limiting the invention in any manner.

EXAMPLE 1

A polyamidoamine adhesion promoter was produced via the following method. A clean 2 L three-necked flask equipped with stirrer, thermometer, and reflux condenser with a Dean Stark trap was charged with 50 parts by weight of a polyamine blend mainly consisting of triethylene tetramine and aminoethyl piperazine and 100 parts by weight of diethylene glycol at room temperature. This mixture was heated to 50°-100° C., at which time 50 parts by weight of JONCRYL® 678 (a styrene-acrylic resin manufactured by S.C. Johnson, Inc.) were slowly added to the flask while agitating. The mixture was heated at 240°-250 C. for six hours before being allowed to cool. The resulting adhesion promoter is hereafter referred to as AP#1.

EXAMPLE 2

A preferred adhesion promoter was produced via the following method. To the same type of reaction apparatus described in Example 1 above was charged 100 parts by weight of polyamine blend (mainly consisting of triethylene tetramine and aminoethyl piperazine) and 75-100 parts by weight of a tall oil fatty acid blend containing less than 5% rosin. The addition occurred at room temperature and resulted in an exothermic reaction. The reaction mixture was heated to 100°-120° C. and 50-75 parts by weight of JONCRYL® 680 (a styrene-acrylic resin manufactured by S.C. Johnson) was slowly added with agitation to the flask and heating to 240°-260° C. resumed. After a reaction time of six hours at this temperature the products were allowed to cool. The resulting adhesion promoters are hereafter referred as AP#2 and AP#3.

EXAMPLE 3

A preferred adhesion promoter was produced via the same method as described in Example 2 but in lieu of the tall oil fatty acid blend either DIACID® 1550 (a tall oil fatty acid-acrylic acid adduct commercially available from Westvaco, Inc.) or a tall oil fatty acid modified with fumaric acid was used. The range of ratios of DIACID® 1550 to JONCRYL® 680 to polyamine blend was 80:40:100 to 120:30:100 by weight. The resulting adhesion promoters are hereafter referred to as AP#4 and AP#5. The ratio of fumarated tall oil fatty acid (15 parts by weight fumaric acid per 100 parts of weight tall oil fatty acid reacted at 200° C.) to JONCRYL® 680 to polyamine blend was 80:40:120. The resulting adhesion promoter is hereafter referred to as AP#6.

EXAMPLE 4

A preferred adhesion promoter was produced in the same reaction flask via the following method. One hundred parts by weight of the polyamine blend used in Example 2 was charged and heated to 100°-120° C. One hundred parts by weight of crushed tall oil rosin containing less than 10% tall oil fatty acids were slowly added to the flask while agitating the polyamine blend. The addition rate was adjusted in such a way that enough time was allowed for the added rosin to form the polyamine salt and the formation of big clumps of agglomerated rosin could be avoided. Heating was resumed to 150° C. when 30 parts by weight of JONCRYL® 680 (a styrene-acrylic resin manufactured by S.C. Johnson, Inc.) were slowly added and heating to 230°-250° C. was resumed. After 6 hours reaction time at this temperature the product was allowed to cool to room temperature, at which time 100 parts of diethylene glycol were added in order to lower the viscosity of the adhesion promoter. The resulting polyamidoamine adhesion promoter is hereafter referred to as AP#7.

EXAMPLE 5

Adhesion promoters were produced via the same method noted above but in lieu of JONCRYL® 680 other styrene-acrylic acid copolymers manufactured by S.C. Johnson, Inc. (JONCRYL® resins), by Morton International (MOREZ® resins), by Air Products (VANCRYL® resins), by Westvaco (JONREZ® resins), and other manufacturers of similar alkali-soluble acrylic resins were used in combination with polyamines.

EXAMPLE 6

This example illustrates the invention methods utilizing the adhesion promoters produced in Examples 1-5 in anionic emulsions prepared with a sodium soap of tall oil (M28B) which were combined with granitic aggregate from Georgia. An emulsion was prepared from Amoco EB-20 asphalt at 65% asphalt residue using 0.8% tall oil soap (based on the weight of the emulsion) at pH 11.5. The emulsion was allowed to cool to 140° F. at which temperature the adhesion promoter (generally 0.3% based on the weight of the emulsion) was added to the emulsion and held at this temperature for at least one hour. Then it was mixed with aggregate retained on U.S. standard sieve No. 8 or 16. Sufficient emulsion was used to achieve a uniform coating of the aggregate. The mixes were allowed to dry for two days at ambient temperature.

To determine the efficiency of the methods utilizing the respective adhesion promoters the cured mixes were placed in a basket which was introduced into boiling water for ten minutes. After the basket was removed, the aggregate was spread on a clean paper towel and allowed to cool. The percent of retained asphalt coat on the aggregate was judged visually after placing the sample in a shallow glass pan filled with cold water and by illuminating the coated aggregate surfaces with a 60 watt lamp. The evaluation results are listed in Table I below.

                                      TABLE I                                      __________________________________________________________________________     Evaluation of Adhesion Promoters with Anionic Asphalt Emulsion and             Granite                                                                        Asphalt: Amoco EB-20, 65% Asphalt Residue                                      Emulsifier: Tall oil (M28B), 0.8%, pH 11.5                                     Aggregate: Granite (Georgia) passing No.4 sieve, retained on No. 8 (16)        sieve                                                                                             %    % Coating                                              Additive                                                                            Composition.sup.a)                                                                           Dosage                                                                              Before Boiling                                                                        After Boiling                                   __________________________________________________________________________     AP#1 JONCRYL ® 678-Amine                                                                      0.3  100    95                                                   Blend (50:50)/DEG (100)                                                   AP#2 L-5-JONCRYL ® 680-Amine                                                                  0.3  100    95                                                   Blend (100:50:100)                                                        AP#3 L-5-JONCRYL ® 680-Amine                                                                  0.3  100    95                                                   Blend (75:75:100)                                                         AP#4 DIACID ® 1550-JONCRYL ®                                                              0.3  100    95                                                   680-Amine Blend (80:40:100)                                               AP#5 DIACID ® 1550-JONCRYL ®                                                              0.3  100    95                                                   680-Amine Blend                                                                (120:30:100)                                                              JONCRYL ®®                                                                  0.3           100  95                                                          680-Amine Blend (80:40:120)                                               AP#7 Rosin-JONCRYL ® 680-                                                                     0.3  100    95                                                   Amine Blend (120:30:100)                                                  Controls           0    100     0                                              AP#8 L-5-Triethylene teramine                                                                     0.3  100    30                                                   (162.5:100)                                                               AP#9 L-5-Amine Blend (150:100)                                                                    0.3  100    40                                              AP#10                                                                               Tallow triamine                                                                              0.3  Emulsion broke                                                                        --                                              AP#11                                                                          Amine BlendD ®                                                                  0.3           100  40                                                          (100:100)                                                                 __________________________________________________________________________      .sup.a) Joncryl 678, 680: styreneacrylic resin (S.C. Johnson, Inc.) Amine      Blend: consisting of triethylene tetramine and amine ethyl piperazine; L5      Tall oil fatty acid; Diacid 1550: Tall oil fatty acidacrylic acid adduct;      Triacid; tall oil fatty acid fumaric acid adduct. DEG: diethylene glycol.

The results noted in Table I clearly show the increased efficiency of the methods utilizing the novel adhesion promoters disclosed herein, especially when compared to conventional adhesion promoters such as tall oil- or modified tall oil-based polyamine condensates or tallow polyamines.

EXAMPLE 7

Using the evaluation procedures described in Example 6 above, a series of tests were conducted to show the efficiency of the adhesion promoters of this invention prepared from MOREZ® acrylic resins (manufactured by Morton International) and evaluated in an emulsion prepared of Exxon 125/150 penetration asphalt in combination with granite from South Carolina. The evaluation results are listed in Table II below.

                                      TABLE II                                     __________________________________________________________________________     Evaluation of Adhesion Promoters in Anionic Asphalt Emulsions                  in Combination with Granite                                                    Asphalt: Exxon 125/150 penetration Asphalt, 65% Asphalt Residue                Emulsifier: Tall oil (M28B), 0.8%, pH 11.5                                     Aggregate: Granite (South Carolina), Retained on 1/2" U.S. Standard            Sieve                                                                                             %    % Coating                                              Additive                                                                            Composition.sup.a)                                                                           Dosage                                                                              Before Boiling                                                                        After Boiling                                   __________________________________________________________________________     AP#12                                                                               MOREZ ® 300-Amine Blend                                                                  0.3  100    90                                                   (60:50)/DEG (100)                                                         AP#13                                                                               MOREZ ® 300-Amine Blend                                                                  0.3  100    90                                                   (40:50)/DEG (100)                                                         AP#14                                                                               L-5-MOREZ ® 300-Amine                                                                    0.3  100    95                                                   Blend (100:50:100)                                                        AP#14                                                                               L-5-MOREZ ® 300-Amine                                                                     0.25                                                                               100    80                                                   Blend (100:50:100)                                                        AP#14                                                                               L-5-MOREZ ® 300-Amine                                                                    0.2  100    80                                                   Blend (100:50:100)                                                        AP#15                                                                               L-5-MOREZ ® 300-Amine                                                                    0.3  100    95                                                   Blend (150:30:100)                                                        AP#16                                                                               L-5-JONCRYL ® 680-Amine                                                                  0.3  100    95                                                   Blend (120:30:100)                                                        Control            0    100     0                                              __________________________________________________________________________      .sup.a) Morez 300: styreneacrylic resin (Morton international); L5: tall       oil fatty acid; Joncryl 680; styreneacrylic resin (S.C. Johnson, Inc.);        Amine blend: consisting of triethylene tetramine and amino ethyl               piperazine; DEG: diethylene glycol.                                      

This example shows the efficiency of methods utilizing styrene-acrylic resin-derived polyamine condensates and of tall oil fatty acid/acrylic resin-derived polyamine condensates as adhesion promoters.

EXAMPLE 8

Using the evaluation procedures described in Example 6 above, a series of tests were conducted to show the efficiency of the adhesion promoters of this invention containing anionic SBR latex (Butonal NS-120, manufactured by BASF) and evaluated in an emulsion prepared of Exxon 125/150 penetration asphalt in combination with granite from South Carolina. The evaluation results are listed in Table III below.

                                      TABLE III                                    __________________________________________________________________________     Evaluation of Adhesion Promoters in Polymer Latex-modified Asphalt             Emulsions in Combination with Granite                                          Asphalt: Exxon 125/150 Penetration Asphalt, 65% Asphalt Residue                Polymer: 3% (as is) SBR-Latex (Butonal NS-120, BASF)                           Emulsifier: Tall oil (M28B), 0.8%, pH 11.5                                     Aggregate: Granite (South Carolina), Retained on 1/2" U.S. Standard            Sieve                                                                          Adhesion           %    % Coating                                              Promoter                                                                            Composition.sup.a)                                                                           Dosage                                                                              Before Boiling                                                                        After Boiling                                   __________________________________________________________________________     AP#16                                                                               L-5-JONCRYL ® 680-Amine                                                                  0.3  100    95                                                   Blend (120:30:100)                                                        AP#16                                                                               L-5-JONCRYL ® 680-Amine                                                                   0.25                                                                               100    90                                                   Blend (120:30:100)                                                        AP#17                                                                               L-5-MOREZ ® 300-Amine                                                                    0.3  100    95                                                   Blend (120:30:100)                                                        AP#15                                                                          Amine BlendREZ ®                                                                0.3           100  90                                                          (150:30:100)                                                              AP#15                                                                               L-5-Amine Blend (150:30:100)                                                                  0.25                                                                               100    95                                              AP#18                                                                               C-3B-MOREZ ® 300-Amine                                                                    0.25                                                                               100    95                                                   Blend (150:30:100)                                                        Controls           0    100    10                                              AP#19                                                                               INDULIN AS-Special                                                                           0.3  100    60                                              AP#19                                                                               INDULIN AS-Special                                                                            0.25                                                                               100    30                                              __________________________________________________________________________      L-5, C3B: tall oil fatty acids Morez 300: styreneacrylic resin (S.C.           Johnson, Inc.) Joncryl 680: styreneacrylic resin (Morton International)        Amine blend: consisting of amine ethyl piperazine and triethylene              tetramine INDULIN ASSpecial: tall oil fatty acid amido amines.           

This example indicates that methods utilizing polyamidoamines derived from tall oil/acrylic resin blends are more efficient at promoting adhesion than conventional tall oil-derived amidoamines.

EXAMPLE 9

Using the evaluation procedures described in Example 6 above, a series of tests were conducted to show the efficiency of the novel adhesion promoters of this invention when utilized with quartzite river gravel (which is notorious for asphalt-stripping). The evaluation results are listed in Table IV below.

                  TABLE IV                                                         ______________________________________                                         Evaluation of Adhesion Promoters in Polymer Latex-Modified Anionic             Asphalt Emulsions in Combination with Quartzite                                Asphalt: Exxon 125/150 penetration Asphalt, 65% Asphalt Residue                Polymer: 3% (as is) SBR-Latex(Butonal NS-120,BASF)                             Emulsifier: Tall oil (M28B), 0.8%, pH 11.5                                     Aggregate: Quartzite (River Gravel, South Carolina),                           retained on No.4 U.S. Standard Sieve                                                                            % Coating                                     Adhesion                %        Before                                                                               After                                   Promoter                                                                              Compoisition.sup.a)                                                                             Dosage   Boiling                                                                              Boiling                                 ______________________________________                                         AP#16  L-5-JONCRYL ® 680-Amine                                                                     0.3      100   70                                             Blend (120:30:100)                                                      AP#16  L-5-JONCRYL ® 680-Amine                                                                     0.25     100   40                                             Blend (120:30:100)                                                      AP#14  L-5 MOREZ ® 300-Amine                                                                       0.3      100   50                                             Blend (100:50:100)                                                      AP#14  L-5 MOREZ ® 300-Amine                                                                       0.25     100   40                                             Blend (100:50:100)                                                      AP#18  C-3B-MOREZ ® 300-Amine                                                                      0.3      100   60                                             Blend (150:30:100)                                                      Controls                0        100   10                                      AP#19  INDULIN AS-Special                                                                              0.3      100   40                                      AP#19  INDULIN AS-Special                                                                              0.25     100   20                                      ______________________________________                                          .sup.a) L5, C3B: tall oil fatty acids,                                         Joncryl 680: styreneacrylic resins (S.C. Johnson, Inc.)                        Morez 300: styreneacrylic resins (Morton Intemational) Amine                   Amine Blend: consisting of triethylene and amino ethyl piperazine              INDULIN ASSpecial: tall oil fatty acid amido amine.                      

This example shows the improved performance of methods utilizing polyamidoamines derived from tall oil/styrene-acrylic resin blends vis-a-vis conventional tall oil-based amidoamines.

EXAMPLE 10

This example shows the improved performance of the invention adhesion promoters with quartzite aggregate which is known to strip asphalt from its surface when exposed to water.

Using the evaluation procedures described in Example 6 above, a series of tests were conducted to show the efficiency of the novel adhesion promoters of this invention when utilized with quartzite aggregate (which is known to strip asphalt from its surface when exposed to water). The evaluation results are listed in Table V below.

                  TABLE V                                                          ______________________________________                                         Evaluation of Adhesion Promoters in Anionic                                    Emulsions in Combination with Quartzite                                        Asphalt: Amoco EB-20 Asphalt (A), 65% Asphalt Residue                          Exxon 125/150 Penetration Asphalt (B), 65% Asphalt Residue                     Emulsifier: Tall Oil (M28B), 0.8%, pH 11.5                                     Aggregate: Quarzite (River Gravel, South Carolina), retained on 1/2"           U.S.                                                                           Standard Sieve                                                                                                  % Coating                                     Adhesion               % Dosage  Before                                                                               After                                   Promoter                                                                              Composition.sup.a)                                                                             (Asphalt) Boiling                                                                              Boiling                                 ______________________________________                                         AP#20  L-5-JONCRYL ® 680-                                                                         0.3       100   85                                             Amine Blend     (A)                                                            (100:50:87.5)                                                           AP#16  L-5-JONCRYL ® 680-                                                                         0.3       100   85                                             Amine Blend     (A)                                                            (120:30:100)                                                            AP#16  L-5- JONCRYL ® 680-                                                                        0.3       100   85                                             Amine Blend     (B)                                                            (120:30:100)                                                            AP#13  MOREZ ® 300-Amine                                                                          0.3       100   80                                             Blend (40:50)/DEG (100)                                                                        (B)                                                     AP#21  MOREZ ® 100-Amine                                                                          0.3       100   80                                             Blend (50:50)/DEG (100)                                                                        (B)                                                     AP#9   L-5-Amine Blend 0.3       100   10                                             (150:100)       (A)                                                     AP#22  INDULIN AS-101  0.3       100   20                                                             (A)                                                     AP#22  INDULRN AS-101  0.3       100   20                                                             (B)                                                     Control                0 (A,B)   100   0                                       ______________________________________                                          .sup.a) L5: tall oil fatty acid                                                Joncryl 680: styreneacrylic acid resin (S.C. Johnson, Inc.)                    Morez 300, 100: styreneacrylic acid resin (Morton Intemational)                Amine Blend: consisting of amino ethylpiperazine and treithylene triamine      DEG: diethylene glycol;                                                        INDULIN AS101: tall oil acid amido amine.                                

This Example shows the improved performance of methods utilizing polyamidoamines obtained from styrene-acrylic resins or tall oil fatty acid/styrene-acrylic resin blends when compared to conventional tall oil fatty acid-derived amidoamines.

It is clear that the novel adhesion promoter compositions taught herein achieved superior results when compared to conventional adhesion promoters used for asphalt/aggregate compositions. Many modifications and variations of the present invention will be apparent to one skilled in the art in light of the above teaching. It is understood therefore that the scope of the invention is not to be limited by the foregoing description, but rather is to be defined by the claims appended hereto. 

What is claimed is:
 1. An improved method for enhancing adhesion between asphalt and aggregate in anionic bituminous emulsions wherein the improvement comprises the addition to the emulsion of a composition comprising the polyamidoamine condensation reaction products of:(A) 20-80 wt. % of a copolymer, formed by reacting(1) 1-99 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with (2) 99-1 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and (B) 80-20 wt. % of a polyamine.
 2. The method of claim 1 wherein the composition comprises the polyamidoamine condensation reaction products of:(A) 30-70 wt. % of a copolymer, formed by reacting(1) 20-80 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with (2) 80-20 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and (B) 70-30 wt. % of a polyamine.
 3. The method of claim 1 wherein the copolymer has a number average molecular weight in the range of about 1,000 to about 10,000.
 4. The method of claim 1 wherein the polyamine has a number average molecular weight in the range of about 60 to about 1,000.
 5. The method of claim 1 wherein the polyamine is a member selected from the group consisting of aminoethylethanolamine, aminoethylpiperazine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexaethyleneheptamine, bis-aminopropylamine, pentamethylenediamine, hydroxyethylpiperazine, bis-hexamethylenetriamine, homologs, and combinations thereof.
 6. The method of claim 1 wherein the composition is dispersed in a solvent selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, alkanolamines, and combinations thereof.
 7. An improved method for enhancing adhesion between asphalt and aggregate in anionic bituminous emulsions wherein the improvement comprises the addition to the emulsion of a composition comprising the polyamidoamine condensation reaction products of:(A) 20-80 wt. % of a mixture containing:(1) 20-80 wt. % of a copolymer formed by reacting(a) 1-99 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with (b) 99-1 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and (2) 80-20 wt. % of a member selected from the group consisting of rosin, C₂₃ -C₂₄ modified rosins, C₈ -C₂₀ fatty acids, C₉ -C₂₂ modified fatty acids, and combinations thereof; and (B) 80-20 wt. % of a polyamine.
 8. The method of claim 7 wherein the composition comprises the polyamidoamine condensation reaction products of:(A) 30-70 wt. % of a mixture containing:(1) 20-80 wt. % of a copolymer formed by reacting(a) 20-80 wt. % of a member selected from the group consisting of α-methyl styrene, styrene, and combinations thereof, with (b) 80-20 wt. % of a member selected from the group consisting of acrylic acid, metacrylic acid, alkyl esters of acrylic acid, alkyl esters of metacrylic acid, and combinations thereof; and (2) 80-20 wt. % of a member selected from the group consisting of rosin, C₂₃ -C₂₄ modified rosins, C₈ -C₂₀ fatty acids, C₉ -C₂₂ modified fatty acids, and combinations thereof; and (B) 70-30 wt. % of a polyamine.
 9. The method of claim 7 wherein the copolymer has a number average molecular weight in the range of about 1,000 to about 10,000.
 10. The method of claim 7 wherein the polyamine has a number average molecular weight in the range of about 60 to about 1,000.
 11. The method of claim 7 wherein the polyamine is a member selected from the group consisting of aminoethylethanolamine, aminoethylpiperazine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexaethyleneheptamine, bis-aminopropylamine, pentamethylenediamine, hydroxyethylpiperazine, bis-hexamethylenetriamine, homologs, and combinations thereof.
 12. The method of claim 7 wherein the composition is dispersed in a solvent selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, alkanolamines, and combinations thereof. 